Analysis of optimization strategy for trucks in highway traffic with a long tunnel

Analysis of trucks’ impacts on the mixed two-lane highway traffic flow with a long tunnel would be a challenge. It needs to figure out the driving behavior of vehicles passing through different positions of a tunnel, i.e., approach section, entrance section, basic section, exit section, and general section. Also, it requires depicting the different driving patterns of trucks and cars, and the interference between them. To deal with these problems, we propose a modified two-lane cellular automaton traffic model with a long tunnel based on a model previously established by our team. The comparison between the calculated and measured results about flows and speeds shows a good agreement. The numerical result shows that the capacity will be reduced when trucks are mixed in the traffic flow, and the more trucks are, the lower the traffic flow will be. Then the strategy of lane restriction for trucks is recommended from the perspective of traffic optimization. The corresponding traffic properties are investigated, and the results are compared with those obtained from the situation without adopting lane restrictions for trucks. When the truck restriction strategy is applied, there is a notable enhancement in traffic capacity, particularly in the scenario with high traffic volume and large proportion of trucks. We investigate the underlying mechanics by analyzing the change in velocities along the road and vehicles’ spatiotemporal evolution. It reveals that implementing lane restrictions for trucks, especially in scenarios with medium to high traffic volume, can improve lane utilization, increase average speeds, reduce traffic congestion, and enhance traffic flow. Then the strategy proves efficient, and it may offer valuable guidance for traffic management on highways featuring long tunnels.